The HTC Radiant is one of three Windows Phone devices that AT&T is rumoured to announce next week at CES 2012. Little was known about it until a leaked image surfaced today.

It appears to share many similarities with the HTC Titan (which AT&T already offers) but there are also a few differences. These include the camera LED flashes switching sides and what appears to be a larger front-facing camera. It may also not be possible to replace the battery without having it serviced.

There are still no details on the specifications. PocketNow suggests that it will come with a 1.5GHz Snapdragon processor and 512MB of RAM. It may also retain the 4.7-inch WVGA display of the HTC Titan. A larger battery may also have been added to deal with LTE connectivity power consumption.

Both HTC and Samsung appear set to join Nokia in getting LTE Windows Phone devices ready probably sometime in early 2012. According to “people familiar with Microsoft’s plans,” both devices will sport a pre-Tango version of Windows Phone with LTE support.

Little is known about the HTC Radiant. A little more is known about the Samsung device. Codenamed Mandel, it will apparently sport a display larger than the 4.3-inch one found on the Samsung Focus S.

As for carriers that could offer the new devices, WinSupersite’s Paul Thurrott reports that the HTC Radiant and Samsung Mandel will join the Nokia Ace at AT&T. The Nokia Ace will be out first, as early as March 18th with the other two to follow before the middle of 2012. It’s unclear whether any of these will also be offered on Verizon’s LTE network (past rumours suggested Verizon was testing the Lumia 800). Formal announcements could come at CES in early January 2012.